Some pumps were recalled late last year

The recall affects the company’s SynchroMed Implantable Infusion Systems, which deliver timed doses of medication to patents. The U.S. Food and Drug Administration (FDA) has identified four specific defects in the pumps. Since 1996, 14 deaths have been linked to the defects, the Wall Street Journal notes.

Labeling each of the defects as Class 1 recall, the FDA has raised concern over the devices to its highest level.

In December, Medtronic recalled two pump models after reports emerged that they were not delivering proper dosages of medication.

The company said that 11 patients died after medication was injected into the patients’ tissue rather than into the pumps. Another patient was killed by an electrical short and two others died from blockages.